Across:
1 They copy everything (say ‘copy’ when using WALKIE-TALKIES) useful for speaking on the wireless? (WALKIE-TALKIES),
10 Praise (admire) briefly (e) (‘admire’ without ‘e’ = ADMIR-) for a (-A-) novice (learner = -L) (ADMIRAL) running The Fleet (ADMIRAL),
11 Square (-T- square) in Cairo (Cairo = CROA-I-) built (= anagram indicator) with American capital (‘American’ capital = -A) (CROATIA) – it’s bound to remind one of split (Split in CROATIA),
12 Archduke dismisses ache (‘archduke’ dismisses ‘ache’ = rduk = KURD) living on Turkish border (KURD),
13 Ted removed from wetlands (‘Ted’ removed from ‘wetlands’ = wlans = LAWNS) in grassy areas (LAWNS),
15 One of those in 30 across (one of “walks” = WALK) is on all sides today (WALK on four sides of today’s grid),
17 Lousy type (NIT) is undercover by definition (is undercover by ‘definition’ = NIT),
19 Turns up (= reversal indicator), police department (CID = -DIC) restricted film (‘restricted’ film cert = -R-) broadcast (on = NO-) (NORDIC) by Scandinavian (NORDIC),
21 Firm (CO-) rejected (= reversal indicator) over the top (over the top = OTT = -TTO-), new (-N) (COTTON) material (COTTON),
22 Similarly in 10 across (‘admiral’ = BOATMAN) and in The Ark (BOATMAN),
23 Jack (SOCKET) Argyle (Argyle SOCK -) and Lawrence (TE Lawrence = -ET) Back (= reversal indicator) (SOCKET),
25 Bar (PU-B-) admits opening early (opening ‘early’ = -E-) to draw attention (Lo! = -LO) (PUEBLO) in small-town Spain (PUEBLO),
27 Storms out on customers (‘storms’ out on ‘customers’ = cue = CUE) from the snooker club (CUE),
29 Image (IDOL) is from part of Brunei dollar (part of ‘Brunei dollar’ = IDOL),
30 Goes on strike locally (WALKS) for those looking for hikes (WALKS),
31 Agonise over (FRET) bottle of Retsina (bottle ‘of Retsina’= FRET),
34 Bar (KEEP OUT) in castle (KEEP) on holiday (OUT) (KEEP OUT),
35 Frame missing from Afro-American (‘frame’ missing from ‘Afro-American’ = OCARINA) musical instrument (OCARINA),
36 King (-KING) consumed by wealth (wealth = WAL- THE) working (= anagram indicator) on track (DOG) (WALKING THE DOG) exercising the boxers (WALKING THE DOG).
Down:
2 Bill (AD-) Marsh (marsh/swamp = -MIRE-) is writing (from the 3Rs = -R) (ADMIRER) to lover (ADMIRER),
3 Limit (“curb” = “kerb” = KERB) reports (= homophone indicator) – one of those restricts 15 across from going further (KERB restricts ‘walk’),
4 Gets wind (EOLIAN) of exposé (expose = nail = -LIAN) relating to old (-O-) energy (E-) going all the way back (= reversal indicator) (EOLIAN),
5 A (A-) small (-S-) amount of money (-CENT) (ASCENT) for the trip up Carrauntoohil, for instance (ASCENT),
6 State (= homophone indicator) not (“not” = “KNOT”) involved in common whipping? (common whipping knot = type of KNOT),
7 Cutting (EXTRACT) from site (“site” = “cite” = EXTRACT) report (= homophone indicator),
8 Club’s (clubs = STICKS) taking baby steps (WALKING) from the start (= positional indicator) (WALKING STICKS) for those who want to be upwardly mobile (WALKING STICKS),
9 How a thief might get his foot in the door of the bank when they’re expecting him (WALK INTO A TRAP) to take the bait (WALK INTO A TRAP),
14 Melancholic (WISTFUL) comedian (WI-T-) hides last colds (last ‘colds’ = -S-) and bad (= anagram indicator) flu (flu = -FUL) (WISTFUL),
16 Struggles with (VI-ES) nursing head, backaches (head ‘backaches’ = -B-) (VIBES) and feelings (VIBES),
18 Born (B-) with the burden of responsibility (-ONUS) (BONUS) to Commission (BONUS),
20 Half of 21 across (half of ‘cotton’ = COT) for retiring type (COT),
21 Sample of tapioca pudding (sample of ‘tapioca pudding’ = CAP) from Cork (CAP),
24 Cut (-HOLE-) in credit (C-R-) for middleman (middle of ‘man’ = -A) (CHOLERA) would make you sick (CHOLERA),
26 Pat (rub = BUR-) turns up (= reversal indicator) for short (e) ceremony (‘rite’ without ‘e’ = -RIT-) by old (-O) (BURRITO) dishy Mexican type (BURRITO),
27 One of those from the boxing industry (box/container = CARTON) in ring (o) missing from comic strip (‘cartoon’ without ‘o’ = CARTON),
28 Scrape by (EKE OUT) with energy (E-) cocktail (‘cock’ tail = -K-) from Spain (-E) no longer in fashion (not in = OUT) (EKE OUT),
32 Weird leaving fieldwork (‘weird’ leaving ‘fieldwork’ = flok = FOLK) to the ordinary people (FOLK),
33 Piece of pavlova served (a piece of ‘pavlova served’ = VASE) in decorative container (VASE).